Abstract Children with acquired brain injuries (ABI) treated on an inpatient rehabilitation unit are at significant risk for long term functional impairment, highlighting the importance of maximizing the effectiveness and utilization of inpatient rehabilitation therapies. The proposed pilot trial seeks to explore the value of animal-assisted therapy (AAT) during inpatient rehabilitation following pediatric acquired brain injury. To accomplish this objective, we will employ a within subjects cross-over trial; all participants will have a volunteer dog involved in 50% of their physical therapy (PT) and occupational therapy (OT) sessions over a 2-week study period. We will recruit 40 patients between the ages of 6-17 being treated for ABI on the inpatient rehabilitation unit at CCHMC. AAT will consist of integration of a dog from the hospital volunteer dog program in PT and OT sessions, while the non- AAT condition will be treatment as usual (TAU) as identified by the patients' treatment team. We have engaged a highly qualified multidisciplinary team to ensure the safety, feasibility, and effectiveness of the methods. We will accomplish the following aims 1) Examine the effect of AAT on level of patient participation, patient affect, and physiological distress during PT and OT sessions, and 2) Explore the effect of AAT on functional outcomes using a historic cohort comparison group. As an exploratory aim, we will examine a number of variables (injury type/severity, child sex and anthropomorphism, therapist factors, and dog handler factors) to begin to determine which patients are most likely to benefit from AAT during inpatient rehabilitation for ABI, and potential mechanisms of action. Qualitative feedback from patients, families, and care providers (therapists, medical team, and dog handlers) will be collected at the completion of their engagement in the trial to determine feasibility and satisfaction with the intervention as well as potential barriers and areas for improvement. We hypothesize that the utilization of ATT in PT and OT sessions will be associated with increased patient participation, greater positive affect, and lower levels of physiological distress compared to TAU. Additionally, it is expected that the study sample will demonstrate greater improvement in functional outcomes than a historical cohort comparison group. Findings will provide evidence regarding the utility of AAT for inpatient rehabilitation of ABI and have the potential to inform and improve clinical care. If successful, this pilot will lay the foundation for transforming rehabilitation interventions for a difficult-to-engage population at risk for significant long-term functional deficits.